//http://isotopescreencapture.codeplex.com/ //The MIT License (MIT) using System.Collections.Generic; using System.Linq; namespace Isotope.Collections.Ranges { public static partial class EnumerableUtil { public static IEnumerable<T> Single<T>(T item) { yield return item; } /// <summary> /// Given a range (start,end) and a number of steps, will yield that a number for each step /// </summary> /// <param name="start"></param> /// <param name="end"></param> /// <param name="steps"></param> /// <returns></returns> public static IEnumerable<double> RangeSteps(double start, double end, int steps) { // for non-positive number of steps, yield no points if (steps < 1) { yield break; } // for exactly 1 step, yield the start value if (steps == 1) { yield return start; yield break; } // for exactly 2 stesp, yield the start value, and then the end value if (steps == 2) { yield return start; yield return end; yield break; } // for 3 steps or above, start yielding the segments // notice that the start and end values are explicitly returned so that there // is no possibility of rounding error affecting their values int segments = steps - 1; double total_length = end - start; double stepsize = total_length / segments; yield return start; for (int i = 1; i < (steps - 1); i++) { double p = start + (stepsize * i); yield return p; } yield return end; } public static IEnumerable<TGROUP> GroupByCount<T, TGROUP>( IEnumerable<T> items, int group_size, System.Func<int, TGROUP> func_new_col, System.Action<TGROUP, int, T> func_add) where TGROUP : class { if (items == null) { throw new System.ArgumentNullException("items"); } if (group_size < 1) { throw new System.ArgumentOutOfRangeException("group_size"); } if (func_new_col == null) { throw new System.ArgumentNullException("func_new_col"); } if (func_add == null) { throw new System.ArgumentNullException("func_add"); } int cur_group_size = 0; TGROUP cur_group = null; foreach (var item in items) { if (cur_group_size == 0) { if (cur_group == null) { cur_group = func_new_col(group_size); } else { throw new System.InvalidOperationException(); } } func_add(cur_group, cur_group_size, item); cur_group_size++; if (cur_group_size == group_size) { yield return cur_group; cur_group = null; cur_group_size = 0; } } if (cur_group_size > 0) { if (cur_group == null) { throw new System.InvalidOperationException(); } yield return cur_group; } } public static IEnumerable<TGROUP> GroupByCount<T, TGROUP>(ICollection<T> items, ICollection<int> group_sizes, System.Func<int, TGROUP> func_new_col, System.Action<TGROUP, int, T> func_add) { if (items == null) { throw new System.ArgumentNullException("items"); } if (group_sizes == null) { throw new System.ArgumentNullException("group_sizes"); } if (func_new_col == null) { throw new System.ArgumentNullException("func_new_col"); } if (func_add == null) { throw new System.ArgumentNullException("func_add"); } int total_group_sizes = group_sizes.Sum(); if (total_group_sizes != items.Count) { throw new System.ArgumentException("group_sizes must account for all items"); } int items_added = 0; for (int group_index = 0; group_index < group_sizes.Count; group_index++) { int cur_group_size = group_sizes.ElementAt(group_index); if (cur_group_size < 0) { throw new System.ArgumentException("group_sizes contains a negative numver"); } var cur_group = func_new_col(cur_group_size); for (int row_index = 0; row_index < cur_group_size; row_index++) { var cur_item = items.ElementAt(items_added); func_add(cur_group, row_index, cur_item); items_added++; } yield return cur_group; } } public static IDictionary<K, List<V>> Bucketize<K, V>(IEnumerable<V> items, System.Func<V, K> func_get_key, IEqualityComparer<K> ieq) { if (items == null) { throw new System.ArgumentNullException("items"); } if (func_get_key == null) { throw new System.ArgumentNullException("func_get_key"); } var dic = new Dictionary<K, List<V>>(ieq); foreach (var item in items) { var key = func_get_key(item); List<V> list = null; bool found = dic.TryGetValue(key, out list); if (!found) { list = new List<V>(); dic[key] = list; } list.Add(item); } return dic; } public static IDictionary<K, List<V>> Bucketize<K, V>(IEnumerable<V> items, System.Func<V, K> func_get_key) { IEqualityComparer<K> ieq = null; return Bucketize<K, V>(items, func_get_key, ieq); } public static IDictionary<K, int> Histogram<K, V>(IEnumerable<V> items, System.Func<V, K> func_get_key, IEqualityComparer<K> ieq) { if (items == null) { throw new System.ArgumentNullException("items"); } if (func_get_key == null) { throw new System.ArgumentNullException("func_get_key"); } var dic = new Dictionary<K, int>(ieq); foreach (var item in items) { var key = func_get_key(item); int old_value = 0; bool found = dic.TryGetValue(key, out old_value); if (!found) { dic[key] = 1; } else { dic[key] = old_value + 1; } } return dic; } public static IDictionary<T, int> Histogram<T>(IEnumerable<T> items) { var dic = Histogram(items, i => i, null); return dic; } public static List<List<T>> Chunkify<T>(IEnumerable<T> items, int chunksize) { var chunks = new List<List<T>>(); List<T> cur_chunk = null; Chunkify(items, chunksize, () => { cur_chunk = new List<T>(chunksize); chunks.Add(cur_chunk); }, item => { cur_chunk.Add(item); }); return chunks; } public static void Chunkify<T>(IEnumerable<T> items, int chunksize, System.Action create_chunk, System.Action<T> add_item) { if (items == null) { throw new System.ArgumentNullException("items"); } if (chunksize < 1) { throw new System.ArgumentOutOfRangeException("chunksize"); } int item_count = 0; int curchunk_size = 0; foreach (T item in items) { if ((item_count % chunksize) == 0) { create_chunk(); curchunk_size = 0; } add_item(item); item_count++; curchunk_size++; } } } public struct DoubleRange { public readonly double _Lower; public readonly double _Upper; public double Lower { get { return this._Lower; } } public double Upper { get { return this._Upper; } } private DoubleRange(double lower, double upper) { this._Lower = lower; this._Upper = upper; } /// <summary> /// Creates a range from the lower and upper values /// </summary> /// <example> /// (0,0) -> [0] /// (0,1) -> [0,1] /// (0,5) -> [0,1,2,3,4,5] /// (2,5) -> [2,3,4,5] /// </example> /// <param name="lower"></param> /// <param name="upper"></param> /// <returns></returns> public static DoubleRange FromEndpoints(double lower, double upper) { return new DoubleRange(lower, upper); } public double Length { get { return this.Upper - this.Lower; } } public override string ToString() { var invariant_culture = System.Globalization.CultureInfo.InvariantCulture; return string.Format(invariant_culture, "Range({0},{1})", this.Lower, this.Upper); } private static bool _intersects_exclusive(DoubleRange range1, DoubleRange range2) { bool val = (range1.Lower < range2.Lower) && (range1.Upper > range2.Lower); return val; } private static bool _intersects_inclusive(DoubleRange range1, DoubleRange range2) { bool val = (range1.Lower <= range2.Lower) && (range1.Upper >= range2.Upper); return val; } /// <summary> /// Tests if this range interests with another /// </summary> /// <param name="range">the other range</param> /// <returns>true if they intersect</returns> public bool IntersectsExclusive(DoubleRange range) { bool val = _intersects_exclusive(this, range) || _intersects_exclusive(range, this); return val; } public bool IntersectsInclusive(DoubleRange range) { bool val = _intersects_inclusive(this, range) || _intersects_inclusive(range, this); return val; } private static bool _touches(DoubleRange range1, DoubleRange range2) { var val = (range1.Upper == range2.Lower); return val; } /// <summary> /// Tests if this range touches another. For example (1-2) touches (3,5) but (1,2) does not touch (4,5) /// </summary> /// <param name="range">the other range</param> /// <returns>true if they touch</returns> public bool Touches(DoubleRange range) { var val = _touches(this, range) || _touches(range, this); return val; } /// <summary> /// Tests if this range contains a specific double /// </summary> /// <param name="n">the double</param> /// <returns>true if the number is contained</returns> public bool Contains(double n) { return (this.Lower <= n) && (n <= this.Upper); } /// <summary> /// Join this range with another and return a single range that contains them both. The ranges must either touch or interest. /// for example (0,2) amd (3,7) will yield (0,7) /// </summary> /// <param name="range">the other range</param> /// <returns>the merged range</returns> public DoubleRange JoinWith(DoubleRange range) { if (this.IntersectsExclusive(range) || this.Touches(range)) { double new_Upper = System.Math.Max(this.Upper, range.Upper); double new_Lower = System.Math.Min(this.Lower, range.Lower); return DoubleRange.FromEndpoints(new_Lower, new_Upper); } else { throw new System.ArgumentException("Ranges cannot be joined because they do not touch or overlap"); } } public IEnumerable<double> Values { get { double step = 1.0; return this.GetValues(step); } } public IEnumerable<double> GetValues(double step) { if (step <= 0.0) { throw new System.ArgumentOutOfRangeException("step", "must be positive"); } double i = this.Lower; while (i <= this.Upper) { yield return i; i += step; } } } public class SparseDoubleRange { private List<DoubleRange> ranges; public SparseDoubleRange() { this.clear(); } public IEnumerable<DoubleRange> Ranges { get { foreach (var range in this.ranges) { yield return range; } } } public double Count { get { double length = this.ranges.Aggregate(0.0, (old, rng) => old + rng.Length); return length; } } private void clear() { this.ranges = new List<DoubleRange>(); } public int RangeCount { get { return this.ranges.Count; } } public void AddInclusive(double lower, double upper) { var rng = DoubleRange.FromEndpoints(lower, upper); this.Add(rng); } public void Add(DoubleRange range) { var left = new List<DoubleRange>(); var right = new List<DoubleRange>(); foreach (var rng in this.ranges) { if (range.IntersectsExclusive(rng) || range.Touches(rng)) { range = range.JoinWith(rng); } else if (rng.Upper < range.Lower) { left.Add(rng); } else if (range.Upper < rng.Lower) { right.Add(rng); } else { throw new System.InvalidOperationException("Internal Error"); } } this.ranges = left.Concat(EnumerableUtil.Single(range)).Concat(right).ToList(); } public double Lower { get { if (this.ranges.Count < 1) { throw new System.InvalidOperationException("empty"); } return this.ranges[0].Lower; } } public double Upper { get { if (this.ranges.Count < 1) { throw new System.InvalidOperationException("empty"); } return this.ranges[this.ranges.Count - 1].Upper; } } public void RemoveInclusive(int lower, int upper) { var rng = DoubleRange.FromEndpoints(lower, upper); this.RemoveInclusive(rng); } public void RemoveExclusive(int lower, int upper) { if ((upper - lower) > (2 * double.Epsilon)) { var rng = DoubleRange.FromEndpoints(lower + double.Epsilon, upper - double.Epsilon); this.RemoveInclusive(rng); } } public void RemoveInclusive(DoubleRange range) { // if the range doesn't intersect this collection do nothing if (!range.IntersectsInclusive(DoubleRange.FromEndpoints(this.Lower, this.Upper))) { return; } var middle = new List<DoubleRange>(); foreach (var S in this.ranges) { if (!range.IntersectsInclusive(S)) { middle.Add(S); continue; } if ((range.Lower <= S.Lower) && (range.Upper >= S.Upper)) { // disregard S completely continue; } if (range.Lower > S.Lower) { if (S.Lower <= (range.Lower - double.Epsilon)) { var X = DoubleRange.FromEndpoints(S.Lower, range.Lower); middle.Add(X); } } if (range.Upper <= S.Upper) { if ((range.Upper + double.Epsilon) <= S.Upper) { var X = DoubleRange.FromEndpoints(range.Upper, S.Upper); middle.Add(X); } } else { throw new System.InvalidOperationException("internal error"); } } this.ranges = middle; } public DoubleRange? FindRangeContainingNumber(double n) { foreach (var rng in this.ranges) { if (rng.Contains(n)) { return rng; } } return null; } public bool Contains(double n) { var rng = this.FindRangeContainingNumber(n); return rng != null ? true : false; } public override string ToString() { var sb = new System.Text.StringBuilder(); sb.AppendFormat("{0}(", this.GetType().Name); foreach (var rng in this.ranges) { sb.Append(rng.ToString()); } sb.Append(")"); return sb.ToString(); } public IEnumerable<double> Values { get { foreach (var rng in this.Ranges) { foreach (int i in rng.Values) { yield return i; } } } } public IEnumerable<double> GetValues(double step) { foreach (var rng in this.Ranges) { foreach (double i in rng.GetValues(step)) { yield return i; } } } } }